Anyone know of a company that sells a 3" stainless steel mandrel bent downpipe?

 

THere are quite a few of them. Petit, M2, ATR, RP....

 

got any websites that sell all/most of the 3" stainless steel mandrel bent downpipes so that I can buy one? And which do you reccomend?

 

http://www.rx7store.net
Pretty much all the same, some are easier to install then others.
I would spend the extra money to get it Jet-Hot coated.

 

As mentioned, they all work pretty much the same. I'd recommend stainless steel over mild since it's more rust/corrosion proof. I just picked up an RX-7 Fashion (Rick's Rotary Performance) DP a while back; 3", mandrel-bent, and SS. It says $329 on the site, but I paid $290 for it. Since you're in Cali, the shop is in the Bay Area and can expedite one to you if you need it right away.